Find A for Partial Fractions 1/(x+5)^2 (x-1)

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Homework Help Overview

The discussion revolves around finding the coefficients in partial fraction decomposition for rational functions, specifically focusing on the expression 1/(x+5)^2 (x-1). Participants are exploring methods to determine the value of A in the decomposition.

Discussion Character

  • Exploratory, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the setup of the partial fraction decomposition and the values of B and C that have been identified. There are inquiries about the methods to find A, including suggestions to substitute specific values for x and compare coefficients.

Discussion Status

The discussion is active with participants sharing their attempts and reasoning. Some have provided specific values for B and C, while others are questioning the next steps to find A. There is no explicit consensus on the method, but various approaches are being explored.

Contextual Notes

Participants are working under the constraints of homework rules, which may limit the information they can share or the methods they can use. There is also a mention of another problem involving a different rational function, indicating a broader context of learning about partial fractions.

pillar
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1/(x+5)^2 (x-1)
B=(-1/6) C=(1/36)

I can't find the value of A, what method do you use to find it?
 
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pillar said:
1/(x+5)^2 (x-1)
B=(-1/6) C=(1/36)

I can't find the value of A, what method do you use to find it?

b]1/(x+5)^2 (x-1)[/b] = A/(x+5) + B/(x + 5)^2 + C/(x - 1)
Put x = 0.
 
pillar said:
1/(x+5)^2 (x-1)
B=(-1/6) C=(1/36)

I can't find the value of A, what method do you use to find it?

[tex]\frac{1}{(x+5)^{2}(x-1)}[/tex] will disintegrate into [tex]\frac{Ax+B}{(x+5)^{2}} + \frac{C}{x-1}[/tex]

Compare coefficients on both sides to get

A = -1/36
B = -11/36
C = 1/36
 
Ok thank, now what about this problem?

[tex]\frac{(x)^3}{(x+4)^{2}}[/tex] will disintegrate into [tex]x+4[/tex]=[tex]\frac{Ax+B}{(x+4)^{2}}[/tex]

I'm not sure where to go from there, to get the values of A & B.
 
pillar said:
Ok thank, now what about this problem?

[tex]\frac{(x)^3}{(x+4)^{2}}[/tex] will disintegrate into [tex]x+4[/tex]=[tex]\frac{Ax+B}{(x+4)^{2}}[/tex]

I'm not sure where to go from there, to get the values of A & B.

[tex]\frac{(x)^3}{(x+4)^{2}}[/tex] will disintegrate into

[tex]\frac{(x+4-4)^3}{(x+4)^2}[/tex]

which you can expand using the [tex](a+b)^3[\tex\ standard formula and then its the same as the last one. Compare coefficients of powers of x on both sides to get A,B,C and so on.[/tex]
 

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